The present invention relates to an accumulator for an air conditioning system.
Air conditioning systems for the passenger compartment of motor vehicles are well known. In general, these systems comprise two heat exchangers, a compression/circulation device, and a thermal expansion device. One heat exchanger is located inside the passenger compartment and is designed to cool and dehumidify the incoming air (passing through the heat exchange and entering the passenger compartment) through heat absorption. The other heat exchanger is typically located outside of the passenger compartment and is designed to reject the heat generated during compression and absorption. A pair of fluid passages connect the heat exchangers to allow the circulation of a working fluid. The expansion device is positioned in one of the fluid passages. The compressor and an accumulator are positioned in the other fluid passage. The working fluid is pumped by the compressor through the outside heat exchanger, the expansion device, the inside heat exchanger and the accumulator in succession. The fluid enters the expansion device as sub-cooled liquid and exits the expansion device as a mix of liquid with vapour bubbles therein. The mixed fluid enters the inside heat exchanger and absorbs heat, continuing the process of vapour generation within the fluid. The accumulator functions as a separator for the liquid and vapour, allowing substantially only vapour to progress to the compressor. The accumulator can have an inlet pipe and an outlet pipe mounted in the side walls of the accumulator housing. In order to allow a reduction in size of the accumulator, it has been proposed to mount the inlet and outlet pipes in an end wall of the accumulator housing. The latter arrangement has been found to increase the risk of a mixture of liquid and vapour passing through the outlet pipe to the compressor, due to excessive internal agitation, leading to inefficient operation of the air conditioning system and risk of damage to the compressor. In order to overcome this problem, it has been proposed to place a baffle inside the accumulator. However, such an arrangement reduces the storage capabilities of the accumulator, or increases the size of the accumulator, and contributes to increased pressure drop.
It is an object of the present invention to overcome the above mentioned problem.
An accumulator in accordance with the present invention for an air conditioning system comprises a housing having a first end wall, a second end wall, and a side wall joining the end walls; a fluid outlet pipe mounted in, and passing through, the first end wall; and a fluid inlet pipe mounted in, and passing through, the first end wall; wherein the outlet pipe has an open end inside the housing positioned adjacent the first end wall; and wherein the inlet pipe comprises a first section and a second section inside the housing, the first section being attached at one end to the first end wall and being attached at the other end to the second section, the second section being open at at least one end with the or each open end facing a portion of the side wall.
In the present invention, the arrangement of the inlet pipe inside the accumulator housing is such as to reduce and divert the energy of the refrigerant fluid as the fluid enters the housing. Such an arrangement helps to reduce agitation of, and foaming of, the fluid inside the housing, reducing the risk of liquid refrigerant fluid passing into the outlet pipe.